You can use pictures and PDF documents in PDF format, which can't be edited, and you can add watermarks to effectively protect the paper from being stolen and copied.

PDF files use industrial standard compression algorithms, which are usually smaller than PostScript files and are easy to transmit and store. It is also page-independent. A PDF file contains one or more "pages", which can handle each page independently, especially suitable for multiprocessor systems. In addition, a PDF file also contains the PDF version used in the file, as well as the positioning information of some important structures in the file. It is precisely because of its various advantages that PDF files have gradually become the new favorite in the publishing industry.